Poly-2-pyrrolidone is the source of a useful synthetic fiber for the textile industry. The melt-spinnable white solid polymer is produced by the alkaline-catalyzed polymerization of 2-pyrrolidone in the presence of carbon dioxide (see U.S. Pat. No. 3,721,652). Polypyrrolidone so-produced is melt-spun into filaments by extrusion from multi-hole spinnerets. In meltspinning, the polymer composition is extruded in a molten condition at a melt temperature which is generally greater than about 270.degree. C. The extrusion must be carried out with care because of the tendency of the polymer to thermally degrade and revert to monomer. Degradation produces an unacceptable extrudate containing foam or bubbles. If extrusion is attempted to an appreciably lower temperature to avoid thermal decomposition, fibers of lower tensile strength are produced. Consequently, in order to melt extrude polypyrrolidone efficiently, one may either seek to increase the thermal stability of the polymer, or to improve the extrudability of the polymeric composition.